CA evaporator coil- the inside story

Here are some shots of the liquid line and its injector tube.

The tube passes through the front passage to the other side.




Here is where it tuns to the back on the other side.


This the passage the tube runs in from front to back.


Here it all is. The 5 center passages get liquid injected into them through little holes in the tube. The two front and back tubes get liquid that is in the headers feed down into them.




As you can see the end is of course brazed shut so all the refrigerant has to go out the injector holes.

Yep the little holes must have been plugged on yours.

Here is a pic I made after labeling the flow on the side. The front and back two passes must just fill by gravity. With the equalizer tube between the headers the suction of the compressor would not directly pull it through those four passages.

That first little hole is the only place the refrigerant comes out of when flow is severely restricted. There's a tiny dot of frost around where it is. There's a lot to take in with your pics, but one thing I notice is I can see why the equaliser tube connections are so prone to leaking - there's not much mechanical strength at the joins.

I'm curious if this evaporator was left exposed to the atmosphere for a long time or if there is a chance a sealed system could have such corrosion.

That evaporator has been cut off of a unit two years or so. I don't remember the unit. It would have been a CA2B. I am much more willing to kill those than the CA2A.

Honestly, I think if you want something that looks like a CA form B, you might as well get a CK and not deal with all the CA issues.

Funnily enough, that thought has crossed my mind during the more frustrating times...except that I don't have the luxury of being able to choose what model I have.
Anyway, that would be giving in and taking the easy way out, and I wouldn't have learned anything. Besides, I think it's quaint having methyl formate in my fridges instead of the common refrigerants. Really, the CA issues are things which once fixed shouldn't return; as demonstrated with my CA-1. The problems with my CA-2 were really a result of how it was previously treated, not an inherent fault as such.
I guess the point is that someone can just buy a CK and use it, whereas a CA always has to be restored. On that basis I'd never recommend a CA to someone unable to do the work.
Just imagine if I was in the U.S. and advertised for non working CA form B's...I'd be inundated